Wiper blade for motor vehicle windows

ABSTRACT

A wiper blade ( 10 ) is proposed that serves to clean windows ( 30 ) of motor vehicles. The wiper blade has a bandlike, elongated, spring-elastic support element ( 12 ) for an elongated rubber-elastic wiper element ( 32 ) that can be pressed against the window and is disposed on the lower band face oriented toward the window and is oriented longitudinally parallel to the support element, and having a coupling part ( 16 ) toward the wiper blade, positioned on the upper band face of the support element remote from the window, for pivotably connecting the wiper blade ( 10 ) to a counterpart coupling part ( 18 ) belonging to a reciprocatingly driven wiper arm ( 20 ), in which the pivot axis ( 40 ) located in the longitudinal center portion of the support element is disposed substantially transversely to the longitudinal extent of the wiper blade ( 10 ), and the coupling part ( 16 ) with its flat underside is oriented toward the upper band face of the support element. This particularly effective wiping is achieved even with problematic window curvatures, if support element ( 12 ) is curved over its entire length such that the center portion of the support element ( 12 ), resting unstressed on the window ( 30 ), is farther away from the window than its two end portions, and if furthermore that the contact face ( 80 ) between the support element ( 12 ) and the underside of the coupling part ( 16 ), measured in the longitudinal direction of the wiper blade, is less than 1.5 times the maximum width ( 68 ) of the support element ( 12 ).

PRIOR ART

In wiper blades for windows of motor vehicles having an elongated,spring-elastic support element for an elongated rubber-elastic wiperelement, the support element should assure the most uniform possibledistribution of the wiper blade contact pressure, originating in thewiper arm, on the window, over the entire field swept by the wiperblade. By means of a suitable curvature of the unstressed supportelement—that is, when the wiper blade is not resting on the window—theends of the wiper strip, which in wiper blade operation are pressedfully against the window, are urged toward the window by the then-tensedsupport element, even if the radii of curvature of spherically curvedvehicle windows vary for every position of the wiper blade. Thecurvature of the wiper blade must accordingly be somewhat greater thanthe greatest curvature measured in the wiping field of the window to bewiped. Thus the support element replaces the complicated support bracketconstruction that has two spring rails disposed on the wiper strip, asin conventional wiper blades (German published, nonexamined patentapplication DE-OS 15 05 357).

In a known wiper blade (German Patent 12 47 161), the rigid couplingpart toward the wiper blade is solidly riveted to the support element,so that the support element is fully reinforced in its center portion.The contact face between the support element and the underside of thecoupling part thus extends over the entire length of the coupling part,so that this portion cannot contribute to adapting the wiper strip tothe course of the window surface. A teaching similar to the inventioncan be learned from an exemplary embodiment of the known wiper blade,except that there, no information is provided that the reinforced enterportion of the support element or any provisions for overcoming thisdrawback.

ADVANTAGES OF THE INVENTION

In the wiper blade of the present invention, a criterion is met thatlimits the reinforcement of the center portion of the support element towhat is still tolerable without major disadvantages.

In a wiper blade in which the joint between the coupling part and thecounterpart coupling part has pivot pins guided in bearing recesses, aneven better adaptation of the wiper strip to the course of the windowsurface is attained if the contact face between the support element andthe coupling part, measured in the longitudinal direction of the wiperblade, is less than the diameter of the pivot pins.

An optimal adaptation of the wiper strip to the course of the windowsurface is obtained if the contact face between the support element andthe coupling part is equivalent to a line that extends in the directionof the pivot axis and is located inside the projection area of the pivotpins. As a result, the support element does not undergo any stiffeningfrom the coupling part, so that the entire length of the support elementcan be used for adapting the wiper strip to the course of the windowsurface.

For proper alignment of the coupling part on the support element, thecoupling part has a U-shaped cross section, and the inside of the baseof the U forms the underside of the coupling part, and the spacingbetween the two legs of the U from one another is adapted to theexisting maximum width of the support element in the longitudinal centerportion of the support element.

In a further feature of the invention, on the free end of each leg ofthe U, and spaced apart from the underside of the coupling part,attachments oriented in clawlike fashion toward one another, which formbracing means for the support element, are disposed at least in theregion of the contact face between the support element and the couplingpart. The spacing is dimensioned such that when the curved supportelement is introduced, it rests on the attachments with its lower bandface under tension at two points spaced apart from one another, and thatit is braced with the apex region of its upper band face on theunderside of the coupling part. This bracing is linear and is orientedcrosswise to the longitudinal extent of the support element.

An advantageous embodiment of a support element belonging to the wiperblade that can also, however, be used independently in wiper blades of adifferent design, provides that the coupling part has a carrier ofU-shaped cross section and made of metal, whose outer walls are coveredby means of an envelope of U-shaped cross section made from a plastic;and that furthermore pivot pins that belong to the swivel connectionbetween the wiper arm and the wiper blade are disposed on the outerwalls of the legs of the U of the envelope. The metal carrier guaranteesreliable wiper operation even after a relatively long time in operation,while in the choice of material for the envelope, the demand for wiperblade support on the wiper arm can be taken into account.

If the metal carrier has bending tabs that are joined to the base of itsU and that fit over the two longitudinal outer edges of the supportelement, then the coupling part can be joined in a simple way to thesupport element, or in other words firmly clamped to it, by means ofthese bending tabs.

Fastening the plastic envelope to the metal carrier is possible in asimple way by detent locking of the envelope, if the envelope, made ofan elastic plastic, protrudes with its legs of the U past the legs ofthe U of the carrier; and that detent hooks protruding toward oneanother are disposed on the free ends of the legs of the U of theenvelope. In a wiper blade, in which the coupling part is provided withpivot pins, protruding transversely to the longitudinal extent of thewiper blade and belonging to the swivel connection between the wiper armand the wiper blade, which pivot pins are disposed on the end portion ofthe coupling part remote from the drive side of the wiper arm, it ispossible for a spoiler, for instance, disposed on the side of thesupport element remote from the window, to be brought with a leadingface, facing into the relative wind, to near the pivot connection, whichenlarges this leading face and furthermore prevents an unattractive gapfrom forming between the joint and the spoiler. It is understood thatthe application of this feature of the invention can be employedindependently of the invention, wherever a suitably designed couplingpart of the wiper blade is used.

In a wiper blade having a longitudinally split support element, both ofwhose longitudinal edges toward one another rest in lateral longitudinalgrooves of a top strip connected to the wiper strip, the mounting of thecoupling part can be accomplished in a simple way if in a furtherdevelopment of the invention, the coupling part is split longitudinallyof the support element, and each of the two coupling part halves isprovided with a longitudinal groove, oriented toward the respectivelyother coupling part half, for receiving a longitudinal strip with thelongitudinal edges, remote from one another, of the two support elementparts, and the two coupling part halves can be joined to one another.

An especially sturdy connection of the two coupling part halves to oneanother is attained if at least one of the two coupling part halves,made of an elastic plastic, dips with a fingerlike protrusion, fittingover the longitudinal center portion of the support element, into arecess that is present in and associated with the other coupling parthalf.

To simplify mounting, it is provided that the protrusion is provided,near its free end, with a detent shoulder pointing toward its couplingpart half, which shoulder cooperates in detent fashion with the longside, toward it, of the top strip.

The two coupling part halves can no longer be separated unintentionallyfrom one another if a lug disposed on the free end of the protrusion,dips into a recess of the other coupling part half.

An especially stable design of the coupling part is attained if thetongue- or fingerlike protrusions of one coupling part half are providedwith lateral splines, with which guide grooves in the other couplingpart half are associated.

So that the coupling part cannot be displaced on the support elementlongitudinally thereof, the support element, in the region of thecoupling part, is provided with a lateral protrusion, with which arecess in the inside, toward this side, of the coupling part isassociated.

A connection between the wiper blade and the wiper arm that is veryreliable in operation is obtained in a wiper blade, which in itslongitudinal center portion has two pivot pins, aligned with one anotherand forming the pivot axis, which are guided in bearing recesses of thewiper arm, if each bearing recess has a mounting channel, eachassociated with one pivot pin and being open toward the window.

Further advantageous refinements and features of the invention aredisclosed in the ensuing description of exemplary embodiments shown inthe associated drawing.

DRAWING

In the drawing,

FIG. 1 is a perspective basic view of a wiper blade of the invention anda wiper arm belonging to it and represented by dot-dashed lines;

FIG. 2 is a schematic side view of a wiper blade that has been liftedfrom the window by a certain extent;

FIG. 3 is a longitudinal section through a coupling part of the bladefor pivotable connection of the wiper blade to a counterpart couplingpart of the wiper arm, and indicated in dashed lines, a center portionof a support element for a wiper element on which the coupling part ispremounted;

FIG. 4 shows the arrangement of FIG. 3, with the support element in itsoperating position;

FIG. 5 is a section through the arrangement of FIG. 3 taken along theline V—V;

FIG. 6 shows two views and one section of a plastic envelope belongingto a different embodiment of the coupling part;

FIG. 7 shows two views and a section of a metal carrier for the plasticenvelope of FIG. 6;

FIG. 8 shows a section corresponding to FIGS. 6 and 7 through theput-together coupling part joined to the support element;

FIG. 9 shows a further version of a coupling part, which is splitlongitudinally and whose two coupling part halves are shownisometrically in a premounting position;

FIG. 10 is a section through the put-together coupling part of FIG. 9,taken along the line X—X of FIG. 9 through a differently embodiedcoupling part;

FIG. 11 is a longitudinal section taken along the line XI—XI of FIG. 10through a differently embodied coupling part;

FIG. 12 is a basic illustration in side view of a wiper blade joined tothe wiper arm; and

FIG. 13 is a section through the wiper blade of FIG. 12 taken along theline XIII—XIII.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

A wiper blade 10 shown in FIG. 1 has a bandlike elongated spring-elasticsupport element 12. On the upper band face or top side 14 of the supportelement 12, remote from the window to be wiped, a coupling part 16 ofthe wiper blade is secured, by way of which the wiper blade 10 can bejoined to a counterpart coupling part 18, associated with it, of thewiper arm. The counterpart coupling part 18 is solidly joined to a wiperarm 20, one end 22 of which is supported on a motor vehicle body, notshown, where it is driven to swing about a pendulum axis 21. Thecoupling part 18 of the wiper arm is secured to the other, free end 24of the wiper arm 20. The two coupling parts 16 and 18 together form adevice 26 for attaching the wiper blade 10 to the driven wiper arm 20.The other band face 28 of the support element 12 faces the window 30 tobe wiped and is designated the underside of the support element 12. Anelongated rubber-elastic wiper element 32 is disposed, with itslongitudinal axis parallel, on this underside of the support element 12.The wiper arm 20 and thus the wiper blade 10 joined to it is urged inthe direction of the arrow 34 toward the window 30, whose surface to bewiped is represented in FIG. 1 by a dot-dashed line 36. Because thewindow 30, which as a rule is spherically curved, is not a portion of aspherical surface, the wiper blade 10 must be capable of constantlyadapting during its wiper motion (double arrow 38) to the currentposition of the window surface—refer to the pendulum axis 21—with aswinging motion relative to the wiper arm 20. The connection device 26is therefore simultaneously embodied as a swivel connection between thewiper blade and the wiper arm. The pivot axes of the wiper arm 20 andthe wiper blade 10 are both identified in FIG. 1 by reference numeral40, because they coincide when the wiper blade has been mounted on thewiper arm. This accordingly common pivot or swing axis extendssubstantially in the direction of the wiping motion 38.

Since the dot-dashed line 36 is intended to represent the greatestcurvature of the window surface, it can be seen clearly from FIG. 2 thatthe curvature of the wiper blade 10, here resting on the window onlywith its two ends, is greater than the maximum window curvature. Underthe contact pressure (arrow 34 in FIG. 1), the wiper blade presses witha wiper strip, belonging to the wiper element, against the windowsurface 36 over the entire length of the wiper blade. In this process, atension builds up in the bandlike spring-elastic support element 12 thatassures a proper contact of the wiper element 32, or the wiper strip 42,over its entire length on the vehicle window 30.

The particular embodiment of the wiper blade 10, or the coupling part 16belonging to it, will now be described in further detail.

In a first embodiment of the coupling part 16 in FIGS. 3-5, the couplingpart has a substantially U-shaped cross section. Accordingly, it has abase 50 of the U and two legs 52 of the U, which are spaced apart fromone another and extend longitudinally of the support element 12 (FIG.1). In the region of the pivot axis or swing axis 40, clawlikeattachments 54 (FIGS. 3-5) are disposed on the free ends of the two legs52 of the U, aimed at one another via a portion of the coupling part 16.Between the inside 56 of the base 50 of the U and the inside faces 58facing it of the clawlike attachments 54, a spacing remains, which hasbeen identified by reference numeral 60 in FIG. 3. The extent of thespacing between the two cheeks 62, toward one another, of the legs 52 ofthe U has been identified by reference numeral 64 in FIG. 5. Agroovelike recess 66 is also disposed in one leg 52 of the U; thisrecess extends substantially in the direction of the spacing 60 and isopen toward the other cheek 52. A center portion of the aforementionedsupport element 12, which in this center portion has its greatest width68 (FIG. 1) is also shown in dot-dashed lines in each of FIGS. 3-5. Thespacing length 64 is adapted to the greatest width 68 of the supportelement 12 in such a way that the support element is freely movable,properly guided, crosswise to its length. The support element 12 iscurved over its entire length in such a way that the center portion ofthe unstressed support element 12 is farther away from the window 30than its two end portions (FIG. 2). The curvature is dimensioned suchthat the support element 12, introduced between the legs 52 of the U,rests with its top side 14 on the inside 56 of the base 50 of the U,while at the same time the underside 28 of the support element 12 isbraced in prestressed fashion on the two end edges 70 of the clawlikeattachments 54. Thus after the premounting of the support element12—which joins it then to the wiper element 32—a secure three-pointcontact of the support element on the two end edges 70 of theattachments 54 and in its apex region 72 on the inside 56 of the base 50of the U is thus obtained. If from this mounted position (FIG. 4) thewiper blade is placed onto the window 30, the curvature of the supportelement 12 is lessened; initially, the two ends of the wiper element 32take on the bracing function of the end edges 70, because the underside28 of the support element 12 lifts away from this end edges 70, untilthe wiper element or wiper blade has reached its operating positionshown in FIG. 1 and rests over its entire length on the surface 36 to bewiped of the window. The contact face 80 (FIG. 4) between the supportelement 12 and the underside of the coupling part 16—formed by theinside 56 of the base 50 of the U—corresponds to a line that extends inthe direction of the pivot axis 40. The lifting away motion of thesupport element 12 from the end edges 70 is represented by the arrows 74in FIG. 3. During this motion, a protrusion 78) projecting laterallyfrom the support element 12) and engaging the groove 66) is also freelymovable. However, in cooperation with the side faces of the groove 66,it reliably secures against longitudinal displacement between thesupport element 12 and the coupling part 16. FIG. 4 further shows thatthe contact between the support element 12 and the coupling part 16corresponds to a line whose width—shown exaggerated in the drawing—hasbeen designated by reference numeral 80 in FIG. 4. This contact takesplace directly in the region of the pivot axis 40, so that this axis islocated inside the projection areas of pivot pins, which are disposed onone of the two coupling parts 16, 18 and can be guided in bearingrecesses of the other coupling part 18, 16. In a departure from theembodiment just described and shown in FIGS. 3-5, it is also conceivableto provide the protrusion 78 of the support element 12 at the apex ofthe support element 12. Because in that case a relative motion betweenthe support element and the coupling part 16 occurs neither in themounting of the support element nor during wiping operation; it is thenpossible to provide a round recess, for instance, instead of the groove66 and the corresponding leg 52 of the U. During the wiping operation,the support element 12 and along with it the wiper strip 42 can befreely resilient over its entire length in the direction of the doublearrows 82 and can thus optimally adapt itself to the various curvaturesof the window surface 36.

In FIGS. 6-8, a second embodiment of the coupling part 16 of the wiperblade is shown, identified in FIG. 8 by reference numeral 116. As seenfrom FIG. 8, the coupling part 116, is made up of two parts. First, ithas a carrier 118 (FIG. 7) of U-shaped cross section, made from a metal.Accordingly, this carrier has a base 120 of the U, which changes over tolegs 122 extending parallel and spaced apart from one another. The legs122 of the U extend over a relatively large portion of the length of thecarrier 118. Instead of the legs 122 of the U, a bending tab 124 isdisposed on one of the carrier 118; like the legs 122, it is integrallyjoined to the base 120 of the U. The center portion of the base 120 ofthe U is also provided with a shaped recess 126 extending longitudinallyof the carrier 118. The coupling part 116 of the wiper blade alsoincludes an envelope 128 shown in FIG. 6, made of an elastic plastic andacting as a joint, which also has a substantially U-shaped crosssection. The base 130 of the U of the envelope 128 is thus adjoined bytwo legs 132 of the U spaced apart from one another. Pivot pins 136 ofnon-round cross section are disposed on the outsides of the legs 122 ofthe U, and are located on a common axis 134. Furthermore, detent hooks138 oriented counter to one another are provided on the free ends legs132 of the U of the envelope 128, which protrude past the legs 122 ofthe U of the carrier 118; these hooks are disposed at a distance fromthe base of the U that is adapted to the height of the legs 122 of the Uof the carrier 118. The envelope 128 made of an elastic plastic can thusbe snapped onto the carrier 118 with temporary deflection of its U legs132, resulting in the mounting position shown in FIG. 8. For receivingthe recess 126 of the carrier 118, the inside of the base 130 of the Uof the envelope 128 is provided with a corresponding indentation 140.Also shown in FIG. 8 with dot-dashed lines is a cross section throughthe wiper element 142. In this case, the wiper element 142 has a topstrip 143, which is joined to its wiper strip 42 that can be pressedagainst the window 30. One longitudinal groove is disposed in each ofthe sides facing away from one another of the top strip 143. The supportelement, which in the embodiment of FIG. 1 is embodied as a one-pieceelongated spring band, is split longitudinally in the version of FIG. 8,resulting in two support element rails 144 forming the support element,which are each seated with one long edge in the grooves that aredisposed in the top strip 142. The support element rails 144 togethertake on the function of the support element. FIG. 8 also shows that thecoupling part 116, formed of the carrier 118 and the envelope 128, isseated on the support element rails 144 in such a way that their outeredges, remote from one another, are guided freely movably both on theinsides of the legs 122 of the U of the carrier 118 and on the insidesfacing one another of the bending tabs 124. The striplike portion 148 ofthe top strip 142 that protrudes past the support element rails 144 islocated in the recess 126 in the carrier 118. For securing the couplingpart 116 to the support element parts 144, the bending tabs 124 of thecarrier 118 are bent in such a way that they fit over the outer edges ofthe support element rails 144 and rest on the underside of the supportelement rails (FIG. 8). The connection between the coupling part 116 andthe support element 144 is accordingly accomplished solely by the twobending tabs 124. The dimension 125 of the bending tabs 124 measuredlongitudinally of the support element 144 is designed such that acontact face is obtained between the support element and the couplingpart, which is smaller, measured longitudinally of the wiper blade, thenthe diameter 135 of the pivot pins 136. In this case as well, a verygood free mobility of the support element 144 relative to the couplingpart 116 is thus obtained. It is illuminating that the fastening of thedual-substance coupling part 116 is not limited to use in supportelements that are longitudinally split in two. It is entirely imaginableto use such a coupling part 116 with the use of a bandlike one-piecesupport element 12 as in FIG. 1, for instance, as well.

An advantageous feature of the coupling part 16 of FIGS. 1-5 is shown inFIGS. 9 and 10. However, in this exemplary embodiment—as in theexemplary embodiment of FIGS. 6-8—the support element 12 is formed bytwo support element rails 218, which as in the embodiment of FIGS. 6-8rests with one of their long edges in longitudinal grooves 220 that aredisposed in a top strip 226 (FIG. 10) that belongs to the wiper element222 and is joined to the wiper strip 224. As FIG. 9 shows, the couplingpart 216 is split longitudinally of the support element 218. There areaccordingly two coupling part halves 228 and 230, each of which isprovided on its outside with one pivot pin 232. When the two couplingpart halves 228 and 230 are joined together, the two pivot pins 232 havea common pivot axis or swing axis 234 (FIG. 10). In the exemplaryembodiment, the coupling part half 228 has two fingerlike protrusions236, which fit over the longitudinal center axis of the support element218, and with which recesses 238 present in and associated with theother coupling part half 230 are associated. The two coupling parthalves 228 and 230 are made of an elastic plastic. They are eachprovided with a longitudinal groove 240, oriented toward therespectively other coupling part half, and each groove is provided withlong edges, remote from one another, of the support element rails 218for receiving the outer longitudinal strip. The height 242 (FIG. 9) ofthe longitudinal grooves 240 is greater than the thickness of thesupport element rails 218, so that in this embodiment of the couplingpart 216 a similar situation is obtained as has been described inconjunction with FIGS. 3-5, if the support element or the two supportelement rails 218 are correspondingly markedly curved. The dispositionof the fingerlike protrusions 236 of the coupling part half 228 and thedisposition of the recesses 238 in the coupling part half 230 are madesuch that corresponding fingerlike protrusions 244 are obtained on thecoupling part half 230, with which corresponding recesses 246 in thecoupling part half 228 are associated. The various tonguelike orfingerlike protrusions 236 and 244, near their free ends, have a detentshoulder 248, which point toward the respective coupling part half andin the assembled state cooperate in detent fashion with the long side249 oriented toward this shoulder of the top strip 226, once the twocoupling part halves 228, 230 have been joined together and thus holdthe two support element rails 218 in their prescribed position in the.longitudinal grooves 220 of the top strip 226. Furthermore, eachfingerlike protrusion 236 and 244 has a lug 250, disposed on its freeend, which in the assembled state of the two coupling part halves dipsinto a recess 252 of the other coupling part half. When the two couplingpart halves 228 and 230 are joined together, the respective fingerlikeprotrusions 236 and 244 deflect upward somewhat on crossing the topstrip 226. To allow the lugs 250 to reach their recesses 252, thefingerlike protrusions are pressed downward with elastic deformation ofthe top strip 226, until the lugs 250 are seated in their recesses 252,and the detent shoulders 248 cooperate with the corresponding long sidesof the top strip 226. Splitting the support element 218 in two makes itconsiderably easier to mount it on the support element rails 218—whichare already seated in the grooves of the wiper element 222.

An especially stable embodiment of the two coupling part halves 328 and330, forming the coupling part 316, is shown in longitudinal section inFIG. 11, where the tongues 336 of one set of coupling part halves areprovided with lateral splines 338, which are guided in guide grooves340, associated with them, in the region of the recesses 342 of theother coupling part half. Joining together the two coupling part halves328 and 330 is done in this case with temporary deformation of the topstrip 226, because the guide grooves 340 and the splines sliding in themprevent deflection of the fingerlike protrusions.

The fragmentary side view, shown in FIG. 12, of a wiper blade 412provided with a so-called spoiler 410 again has a bandlike support,element 414, on whose underside toward the window there is a wiper strip416. The spoiler 410 (FIG. 13) is located on the top side of the supportelement 414; the spoiler acts a wind deflection strip for the relativewind, which assures a proper contact pressure of the wiper strip 416 onthe window to be wiped, even at high vehicle speeds. As in the exemplaryembodiments already described above, the wiper blade 412 is equipped inits center portion with a connection device 418, which serves to jointhe wiper blade 412 to the driven wiper arm 420. As already described inconjunction with FIG. 1, the connection device has a coupling part 422of the wiper blade and a counterpart coupling part 424 of the wiper arm,cooperating with the coupling part. The coupling part 422 of the wiperblade likewise has two coaxial pivot pins 426, which are guided inbearing recesses 428 of the coupling part 424 of the wiper arm. The twopivot pins 426 are disposed as close as possible to the end portion,facing away from the power takeoff side of the wiper arm 420, of thecoupling part 422 of the wiper blade, so that the spoiler 410 can beguided close to the pivot axis or swing axis.

A characteristic that can be seen from FIG. 12 is of general andparticular importance; it can be employed even independently of theembodiments of the invention that are described and shown here. The twopivot pins 426, disposed in the longitudinal center portion andprotruding from the long sides of the wiper blade, are introduced, frommounting the pivot connection between the wiper arm 420 and the wiperblade 418, into their bearing recesses 428 of the wiper arm via mountingchannels 430; these bearing recesses are opened, beginning at therecesses, toward the window 30 to be wiped. The wiper blade contactpressure (arrow 34) assures an operationally reliable pivot connection,which can be undone itself only after the wiper blade has beenintentionally lifted away from the window. It does not matter whetherthe pivot connection is embodied as a so-called insert and twistconnection—with a non-round peg cross section—or as a detent connection.

It is a common feature of all the exemplary embodiments that the supportelement 12 or 144 or 218 is curved over its entire length in such a waythat the center portion of the support element, pressed without stresson the window 30, is farther away from the window than its two endportions, and that the contact face between the support element and theunderside of the coupling part, measured longitudinally of the wiperblade, is less than 1.5 times the maximum width of the support element.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofconstructions differing from the types described above.

While the invention has been illustrated and described herein as a wiperblade for windows of motor vehicles, it is not intended to be limited tothe details shown, since various modifications and structural changesmay be made without departing in any way from the spirit of the presentinvention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this invention.

What is claimed is:
 1. A wiper blade for windows of motor vehicles,comprising a spring-elastic support element which has a longitudinalextension and along the longitudinal extension has a lower and an upperband surface; a wiper element arranged on the lower band surface of thesupport element; a first coupling part arranged on the upper bandsurface of the support element and having an underside arranged on theupper band surface on and over a contact face and also havingclaw-shaped attachments which engage the support element, said firstcoupling part being cooperatable with a second coupling part belongingto a wiper arm, the support element along its longitudinal extensionbeing curved so that in unstressed condition of the wiper blade thecontact face of the underside of the first coupling part on the upperband surface of the support element in direction of the longitudinalextension is smaller than 1.5 times of the maximal width of the supportelement, and the support element in addition to the contact face is alsosupported on the claw-shaped attachments with prestress so that thesupport element is movable under the first coupling part relative tosaid underside of said first coupling part.
 2. A wiper blade as definedin claim 1, wherein the first coupling part has a U-shaped cross-sectionwith a base and legs, and an inner side of the base forms the undersideof the first coupling part, while a distance between the legs isselected in accordance with a width of the support element so that thesupport element is unobjectionably guided and is freely movable.
 3. Awiper blade as defined in claim 1, wherein the first coupling part isprovided with pivot pins which belong to a pivot connection between thewiper arm and the wiper blade, the pivot pins being arranged on an endportion of the first coupling part which faces away from a power takeoff of the wiper arm.
 4. A wiper blade as defined in claim 1, whereinthe support element is subdivided in a longitudinal direction and haslongitudinal edges which face toward one another, the first couplingpart being split in the longitudinal direction of the support elementand each of two coupling part halves being provided with a longitudinalgroove facing a longitudinal groove of another coupling part half forreceiving a longitudinal strip with longitudinal edges of both supportelement parts facing away from one another, and both coupling parthalves being connectable with one another.
 5. A wiper blade as definedin claim 4, wherein at least one of the coupling part halves composed ofan elastic plastic is introduced, by a finger-shaped protrusion whichoverlaps a longitudinal central axis of the support element, in anassociated recess of another coupling part half.
 6. A wiper blade asdefined in claim 5, wherein the protrusion near its free end is providedwith an arresting shoulder which faces its coupling part half, and thearresting shoulder cooperates with an associated longitudinal side of atop strip in an arresting manner.
 7. A wiper blade as defined in claim5, wherein the protrusion at a free end has a lug which is introducedinto a recess of the upper coupling part half.
 8. A wiper blade asdefined in claim 5, wherein the protrusions of one of the coupling parthalves are formed as protrusions selected from the group consisting oftongue-shaped protrusions and finger-shaped protrusions and are providedwith lateral splines associated with guide grooves of another couplingpart half.
 9. A wiper blade as defined in claim 1, wherein the supportelement in a region of the first coupling part is provided with alateral protrusion which is associated with a recess provided on aninner side of the coupling part facing this side.
 10. A wiper blade asdefined in claim 1; and further comprising pivot pins forming a pivotaxis, the pivot pins being guidable in bearing recesses of the wiperarm, each bearing recess being provided with a mounting passage whichopens toward a window and is associated with a respective pivot pin. 11.A wiper blade for windows of motor vehicles, comprising a spring-elasticsupport element which has a longitudinal extension and along thelongitudinal extension has a lower and an upper band surface; a wiperelement arranged on the lower band surface of the support element; afirst coupling part arranged on the upper band surface of the supportelement and having an underside arranged on the upper band surface onand over a contact face and also having claw-shaped attachments whichengage the support element, said first coupling part being cooperatablewith a second coupling part belonging to a wiper arm, the supportelement along its longitudinal extension being curved so that inunstressed condition of the wiper blade the contact face of theunderside of the first coupling part on the upper band surface of thesupport element in direction of the longitudinal extension is smallerthan 1.5-times of the maximal width of the support element, and thesupport element in addition to the contact face is also supported on theclaw-shaped attachments with prestress, wherein the first coupling parthas at least one pivot pin, and the contact face in the longitudinalextension of the wiper blade is smaller than the diameter of the atleast one pivot pin.
 12. A wiper blade as defined in claim 11, whereinthe contact face between the support element and the first coupling partcorresponds to a line which extends in direction of a pivot axis locatedinside a projection surface of the pin.
 13. A wiper blade for windows ofmotor vehicles, comprising a spring-elastic support element which has alongitudinal extension and a along the longitudinal extension has alower and an upper band surface, a wiper element arranged on the lowerband surface of the support element; a first coupling part arranged onthe upper band surface of the support element and having an undersidearranged on the upper band surface on and over a contact face and alsohaving claw-shaped attachments which engage the support element, saidfirst coupling part being cooperatable with a second coupling partbelonging to a wiper arm, the support element along its longitudinalextension being curved so that in unstressed condition of the wiperblade the contact face of the underside of the first coupling part abutsagainst the upper band surface of the support element in direction ofthe longitudinal extension, the support element in addition to thecontact face is also supported on the claw-shaped extensions; the firstcoupling part has a U-shaped support composed of metal and having outerwalls; a U-shaped envelope composed of plastic and covering the outerwalls of the support; and pivot pins arranged on the outer walls of legsof the envelope.
 14. A wiper blade as defined in claim 13, wherein themetal support has bending parts connected to a base and engaging bothlongitudinal outer edges of the support element.
 15. A wiper blade asdefined in claim 13, wherein the envelope composed of plastic has legsextending outwardly beyond legs of the support; and further comprisingarresting hooks arranged on free ends of the legs of the envelope andprestressing them relative to one another.
 16. A wiper blade as definedin claim 13, wherein the support element in a region of one of thecoupling parts is provided with a lateral protrusion, and is associatedwith a recess provided on an inner side of the coupling part facing thisside.
 17. A wiper blade (10) for windows (30) of motor vehicles, havingan elongated, spring-elastic support element (12) for an elongatedrubber-elastic wiper element (32) that can be pressed against the windowand is disposed on a lower face of the support element (12) orientedtoward the window and longitudinally parallel to the support element,and having a first coupling part (16) with a flat underside positionedon an upper face of the support element remote from the window forpivotably connecting the wiper blade (10) to a second coupling part (18)belonging to a reciprocatingly driven wiper arm (20), in which a pivotaxis (40) located in a longitudinal center portion of the supportelement is disposed substantially transversely to a longitudinalextension of the wiper blade (10), and the first coupling part (16) withits flat underside is oriented toward the upper face of the supportelement, characterized in that the support element (12) is curved overits entire length such that the longitudinal center portion of thesupport element (12), resting unstressed on the window (30), is fartheraway from the window than two end portions of the support element (12),and that a contact face (80) between the support element (12) and theunderside of the coupling part (116), measured in a longitudinaldirection of the wiper blade, is less than 1.5 times a maximum width(68) of the support element (12), that a joint (128) disposed betweenthe first coupling part (16) and the second coupling part (18) has pivotpins (136) guided in bearing recesses, and that the contact face betweenthe support element (12) and the first coupling part (16), measured inthe longitudinal direction of the wiper blade, is less than a diameterof the pivot pins.
 18. A wiper blade (10) for windows (30) of motorvehicles, having an elongated, spring-elastic support element (12) foran elongated rubber-elastic wiper element (32) that can be pressedagainst the window and is disposed on a lower face of the supportelement (12) oriented toward the window and longitudinally parallel tothe support element, and having a first coupling part (116) with a flatunderside positioned on an upper face of the support element remote fromthe window for pivotably connecting the wiper blade (10) to a secondcoupling part (18) belonging to a reciprocatingly driven wiper arm (20),in which a pivot axis (40) located in a longitudinal center portion ofthe support element is disposed substantially transversely to alongitudinal extension of the wiper blade (10), and the first couplingpart (116) with its flat underside is oriented toward the upper face ofthe support element, characterized in that the support element (12) iscurved over its entire length such that the longitudinal center portionof the support element (12), resting unstressed on the window (30), isfarther away from the window than two end portions of the supportelement (12), and that a contact face (80) between the support element(12) and the underside of the first coupling part (116), measured in alongitudinal direction of the wiper blade, is less than 1.5 times amaximum width (68) of the support element (12), that a joint (128)disposed between the first coupling part (116) and the second couplingpart (18) has pivot pins (136) guided in bearing recesses, and that thecontact face (80) between the support element (12) and the firstcoupling part extends in a direction of the pivot axis (40).
 19. A wiperblade (10) for windows (30) of motor vehicles, having an elongated,spring-elastic support element (12) for an elongated rubber-elasticwiper element (32) that can be pressed against the window and isdisposed on a lower face of the support element (12) oriented toward thewindow and longitudinally parallel to the support element, and having afirst coupling part (16) with a flat underside positioned on an upperface of the support element remote from the window for pivotablyconnecting the wiper blade (10) to a second coupling part (18) belongingto a reciprocatingly driven wiper arm (20), in which a pivot axis (40)located in a longitudinal center portion of the support element isdisposed substantially transversely to a longitudinal extension of thewiper blade (10), and the first coupling part (16) with its flatunderside is oriented toward the upper face of the support element,characterized in that the support element (12) is curved over its entirelength such that the longitudinal center portion of the support element(12), resting unstressed on the window (30), is farther away from thewindow than two end portions of the support element (12), that a contactface (80) between the support element (12) and the underside of thefirst coupling part (16), measured in a longitudinal direction of thewiper blade, is less than 1.5 times a maximum width (68) of the supportelement (12), that the first coupling part (16) has a substantiallyU-shaped cross-section, said first coupling part (16) having a base (50)and two legs (52) to form the U-shaped cross-section, said supportelement (12) introduced between the legs (52) of the first coupling part(16), wherein attachments (54) are disposed on free ends of said legs(52) proximate to said pivot axis, and that the support element (12) hasa curvature whereby a top side (14) of the support element (12) rests onan inside portion (56) of the base (50) while an underside (28) of thesupport element (12) is simultaneously braced in a prestressed fashionon end edges (70) of the attachments (54).